An small aircraft pilot was unclr in his mind what ATC meant with 'responsible for your own terrain ...

Attributes
ACN	217931
Time
Date	199208
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bsr airport : mry
State Reference	CA
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mry
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 30 flight time total : 850 flight time type : 200
ASRS Report	217931
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were at 8000 ft. Had just been handed off to mry approach for descent into mry. We were told to expect a visual approach at mry and to report airport in sight. I asked to begin my descent, so as to keep the rate of descent reasonable and was told 'you can descend if you will be responsible for your own terrain clearance.' I replied that I would accept responsibility, and began a descent. Referring to the sectional chart told me I could descend without a terrain problem, although on later consideration, my clearance may have been less than the 2000 ft required in mountainous area. The bigger problem was that I was given no altitude to descend 'to'. Was I already at the MVA? How low could I go? Was there no traffic below me that needed to be separated from me? The problem went away very quickly as I got visual contact with airport and was cleared for a visual approach. If I had it to do over, I would question the controller's rather incomplete clearance. What is the MVA? How low can I descend once clear of terrain? Or I could have requested a contact approach before having airport in sight.

Original NASA ASRS Text

Title: AN SMA PLT WAS UNCLR IN HIS MIND WHAT ATC MEANT WITH 'RESPONSIBLE FOR YOUR OWN TERRAIN CLRNC'.

Narrative: WE WERE AT 8000 FT. HAD JUST BEEN HANDED OFF TO MRY APCH FOR DSCNT INTO MRY. WE WERE TOLD TO EXPECT A VISUAL APCH AT MRY AND TO RPT ARPT IN SIGHT. I ASKED TO BEGIN MY DSCNT, SO AS TO KEEP THE RATE OF DSCNT REASONABLE AND WAS TOLD 'YOU CAN DSND IF YOU WILL BE RESPONSIBLE FOR YOUR OWN TERRAIN CLRNC.' I REPLIED THAT I WOULD ACCEPT RESPONSIBILITY, AND BEGAN A DSCNT. REFERRING TO THE SECTIONAL CHART TOLD ME I COULD DSND WITHOUT A TERRAIN PROBLEM, ALTHOUGH ON LATER CONSIDERATION, MY CLRNC MAY HAVE BEEN LESS THAN THE 2000 FT REQUIRED IN MOUNTAINOUS AREA. THE BIGGER PROBLEM WAS THAT I WAS GIVEN NO ALT TO DSND 'TO'. WAS I ALREADY AT THE MVA? HOW LOW COULD I GO? WAS THERE NO TFC BELOW ME THAT NEEDED TO BE SEPARATED FROM ME? THE PROBLEM WENT AWAY VERY QUICKLY AS I GOT VISUAL CONTACT WITH ARPT AND WAS CLRED FOR A VISUAL APCH. IF I HAD IT TO DO OVER, I WOULD QUESTION THE CTLR'S RATHER INCOMPLETE CLRNC. WHAT IS THE MVA? HOW LOW CAN I DSND ONCE CLR OF TERRAIN? OR I COULD HAVE REQUESTED A CONTACT APCH BEFORE HAVING ARPT IN SIGHT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

An small aircraft pilot was unclr in his mind what ATC meant with 'responsible for your own terrain clearance'.